Draft equalizer for tractor implement hitches



Nov. 17, 1953 H. METZGER l 2,659,286

DRAFT EQUALIZER FOR TRACTOR IMPLEMENT HITCHES Filed Oct. 24, 1949 AEA/R Y ME 7" Z GEI? INVENTOR.

BYM 221 Tanzi,

Patented Nov. 17, ,1953 2,659,286

UNITED STATES PATENT OFFICE DRAFT EQUALIZER Fon TRACTOR IMPLEMENT HrrcHEs Henry Metzger, Mercedes; Tex. Application October 24, 1949, Serial No. 123,215 Claims. (Cl. 97546.07)

My invention relates to a draft of implement whichv isconnected thevcontrol rod for the hyand weight of implement equalizer arm which is draulic system and over which the compression Numbers 1,687,719, 2,118,181 and Reissue 22,642. for controlling'the hydraulic .lift system for the links pivotally support and lift the implement in I have found that in operation of the normally conjunction with a ythird and upper link'which equipped tractor o the Ford and Ferguson type also serves as the pressure control lnk'or com- 15 there 1s no way for the operator tocontrol the spring .which is compressed in response to the in the normally equipped tractor ot this type to suspension system is pivotally attached to a duv spring faster and thus moves the control rod hydraulic lift mechanism for the three point susfast enough to renderfthe proper control to the pression link acting through the duplex crank. th

fixed through which the forces act which forces out of the ground of lightweight implements may the soil engaging implement. The length of this' he arm to suit the conditions of weight of `imarm is equal to the distance in the duplex crank plement and the type f 501'1 This adjustment from its pivotal attachment on the diierential may be made by the operator While the tractor ls housing to the pivotal attachment of the forward in motion.

end of the compression link. It is an object of my invention toprovide a while the tractor is underway, the length of the the compression spring and control rod in a h'yject it is necessary to provide a lever which is It is a further object of my invention to propivoted to the tractor housing; has a pivoted videan arm or lever which is pivoted at its lower attachment for the rear end of the sleeve to end to a tractor, a, pivotal'attachment on this arm above this lower pivot end for attaching the rear end of the control rod and compression spring of an implement lift control system, and a connection movable along this arm for attaching the forward end of the upper or compression link in a three point implement suspension systern for the tractor.

A still further object of my invention is to provide a lever for pivotal attachment to the differential housing tractor which includes a pivoted connecting means above of the control rod and compression spring of the tractors hydraulic implement and a means on the by the operator of the tractor to a position closer to or further away from the lower pivotal end of the lever and to which is attached the forward end of the upper or compression link of the tractors three point implement suspension sys- A still further object of my invention is to provide a U-shaped lever having pivotal means at its lower open end for attachme. t to a tractor, pivot means above this lower pivotal attachment to the tractor for attachment of the rear end of a control rod and compression spring in the hydraulic implement lift control system, a screw rod extending within the U-shaped arm and mounted for rotation within the closed end of the U-shaped arm, a handle for rotating the screw rod, a member slidab-ly mounted on the U- shaped lever provided with screw threads for receiving the screw rod which when rotated along the screw rod and along the slidable forward end a three point a tractor.

For a more complete understanding of the nature and scope of my invention, reference can be had to the following detailed description taken in connection with the accompanying drawings in which:

Figure l is a side view partly in section showing the three point suspension system in a Ford and Ferguson type of tractor with the adjustable length arm incorporated according to my invention;

Figure 2 is a perspective view of my adjustable length connecting lever; and

Figure 3 is a cross-section side elevation of the adjustable length of lever of Figure 2.

Like characters refer to similar parts in the various figures.

In Figure l a tractor of the Ford or Ferguson type is indicated generally at I and has a differential housing shown in section at II to which is pivotally mounted the lower end of my adjustable length lever or arm generally indicated at I2. This adjustable length lever I2 replaces the normal duplex crank found in this type of tractor implement attachment and lift. In general the type of tractor to which my invention may be applied is shown in the above mentioned Ferguson patents. The construction and operation of the Ferguson system used on Ford and Ferguson tractors is well known to those skilled in the art and it will not, therefore, be necessary to describe it in complete detail.

Two lower draft links I3 are pivoted to housing II at their forward ends and are pivotally connected to an implement I4, at their rear ends I3. The implement I4 here shown is a disc plow having discs as indicated at I5 and fio shown in an elevated position. Implement I4 is provided with a frame including a vertically extending part I6 supported by an angle support member I1. The draft links I3 are arranged to be moved vertically by power means comprising in this system a pair of lift arms I3 secured to the opposite ends of a rock shaft I9 extending transversely of the differential housing II and connected by links 20 with the draft links I3.

Within the differential housing the rock shaft carries a lever arm 2I through which the shaft is rocked to lift the arms by the hydraulic motor comprised of the cylinder 22 and piston 23, the piston and arm 2I being coupled by the connecting rod 24. Pressure fluid is supplied to the lift cylinder from a pump, not shown, the flow of uid to and from the cylinder being controlled by the valve 25 adapted to control an inlet port 26 and outlet port 21 and which is connected to a lever 28 of duplex form which is pivoted at 29, engaged at 30 by the tension spring 3I and has its top end 32 normally kept by said spring against the eccentric or cranked part 33 of the shaft shown in broken outline at 34 on which is mounted the manual control lever 35. Since the pivot 29 and crank 33 are movable, the lever 23 may be termed a floating lever. An adjustable stop 36 is provided to determine the maximum depth of depression of the implement. The lever 28 also has two inward projections 31, shown in broken circle outline, which can act as fulcrum means and the pivot 29 is provided on a reciprocable stirrup 33 pivotally attached to a composite rod 39 and sleeve 39a pivotally attached to adjustable length lever I2 which iS pivoted at 40 on the tractor housing II and has connected thereto the upper or compression link 4I.

In Figure 1 the mechanism is shown for a raised position of the implement I4, there being no compression forces acting in the link 4| attached at its forward end to the lever I2. The valve 25 covers both ports 26 and 21 so that there is no movement of oil. In order to lower the implement to working position the manual lever 35 is moved to engage the stop 36 which has been adjusted to a position corresponding to the depth of cut required.

The adjustable length lever I2, see Figures 2 and 3, is made of heavy metal strap material and is bent into a U-shape having an open lower end at 42 and an upper closed end at 43. Toward the open end 42 the sides or legs 44 and 45 of the lever I2 are apertured at 46-46 to receive the pivot mounting pin 40 which pivotally connects the lower end of the lever to the housing II. Slightly above the pivot apertures 46-46 are apertures 41-41 for receiving a pivot pin 48 which pivotally connects the rear end of composite rod 39 and sleeve 39a to lever I2. Surrounding composite pin 39, see Figure l, is a collar 5D abutting at its forward end against a plate 5I which rides against housing II. Surrounding the composite pin 39 and collar 5I) is a balance or compression spring 52 which abutts at its forward end against a ridge 5Ia formed on collar 50 and at its rear end it abutts against a shoulder formed on sleeve 39a. Compression forces acting through upper link 4I are applied through lever I2 to compress the compression control spring 52 and move the composite or control rod 39 connected at its forward end to the linkage actuating the iiuid pressure lift mechanism for the implement.

The means by which the operator of the trac- .tor may'adjust y.the length of the `lever armV I2 trol for .operating the -suspensionqof the imple, through which compression Vforces in lever il ment. Control rod 39 Within Spring 52 is moved act in compressing vspring 52 will now be de.- by lever I2 to actuate the regular linkage .conscribed. Ascrew rod 5.4, see Figure 3, is mounted trolling valve and thence power piston 213 nfor rotation in en aperture 55 formed in the 5 for the lift linkage. upper end 43 of lever I2. The screw rod has a While the tractor is in motion the operator journal portion at lt'whioh rotates inaperture 4Cim easily turn crank 59 to adjust the length .55 and is formed with a collar 5l at its upper lever arm I2. Thus,v as the soil being worked end to which is rigidly iixed a transversely ex varies, for example, from a heavy black to a tending cranked. crank ,sa has a handle 59 io Soft Sand soil, the operator een adjust the Secured at its Outer end which comprises a-post length of arm 2| to compensate .for such variarec and a rotary collar slwhieh may be grasped tion, thereby preventlne the implement from by the hand of the tractor operator from his lopiiig in and olli? of ille ground normal Operating pQSlton on the tractolg yScrew Since it S ObViOllS that Certain further rod 54 is held in lever I2 by a cotter pin'62 Vwhich 15 Changes Caribe made in the'foregoing 'construcpasses through a suitable transversely extending lions Without departing from the Sllirii` and aperture in the rod. Above the cotter pin 62 Scope of this invention, it is intended that all there maybe placeda `waslielras indicated at.63. mattei s hoWnin the aooomloiiying drawings A slidable member generally indicated at e4 0r rdescribed hereinbefore snail be interpreted is mounted between the legs 44 and 45 of the 20 @s illustrativo .and 110i in a limiting Sense.

lever I2 and l's apertured and threaded kat 65 to I claim as Y iiiVontion receive the seretv red 54 which when rotated by l- Hitch means ior connecting an implement crank sa moves member e4 along the lever l2. i0 ,e tractor Vehlele Comprlslhs upper and lower slide member t4 is formed with a eentrdl portion link means Subject to compressive and tensile 66 through Which extends the threaded aperture 25 stresses in resisting turning movement of the 65. The central portion isa block of rectanguf implement Clue to lille diofi llelooli, ille upper lar shape and slides against the inner adjacent of Said lilik moans boing Connected i0 Said treo.- faces of leg members 44 and A5. Formed on the '50i' tlii'oligh .a Variable length lover extending central member 55 are opposltely disposed par.v substantially vertically transverse to said upper allel shoulders e1 and 5a which extend slightly so link means, Seid verleble length lever .comprisbevond the legs 44 and 45 oflevs11 l2 and have a lng a first member pix/ced at its lower end to sliding nt with tne adjaeent edges of these legs .Sald hector end having means positioned above 44 and 45y as best slmwn ln Figure 2.y TWO spaced said lower pivoted end -for attaching a control and parallel lugs 69 and 'I0 are formed 4to extend Tod olif-l Compression ,Spring for alift means from and transversely so shoulder 53 Between 35 for said hitch, a second'member movably pothese spaced lugs 69 and 1e is received the forsitionedolong Sai@ first moiiiboliioiil and Goward end of compression or upper linkl 4I, see Ward Said l0We1"DlVoted ond of the iiiSt momf Figure 1. Two pair of suitable apertures 1I-`II ber' and Screw moons for moving Sold Sooold and 'I2 I2 are formed in the lugs 69 and 7G to member along Said first member: Solid .Second receive a pivot pin 13, see Figure l, which plv- 40 member being pivotally connected to the forward otally secures the forward end of link 4I to the end of Said upper link moans, Wheioby the of' slide c4 en lever l2. In "assembling the slide feci 0f the force-applied by Seid upper link lo member 64, a through belt 'I4 secured toward lille Control Tod ondoompiessioii Spring for the the ends of `thelegs Yt4 and 45 is removed and lift moans .for Said Ahiioh may be yvaried upon the member siisslid inte the open end vi2 of 45 Chenelns the position 0f Seid Second vmember the lever I2 andrscrewgrod 54 is threaded into along Said first memberthe central body 66. Bolt '64 when l'n place pre- 2- In on autom-olio -CleDill -COIiirol for ground vents slide 64 from being removed from the lever. Working implements 0f the ltype in which a ylink In opergtionforces Vacting in upper or c0m and'control rod are rmoved by `forces resulting pression link 4I are applied to the lever I2 to- 50 from all lmlflment Working in the ground loopto the distance between pivot 13 and pivot an, end effect Such depth control, means for adsee Figure 1 Thus if a lightweight implement 55 Justably coupling said link to said control rod is ,being used and the slide 54 is ln lts upperwhereby the forces in said link act through said most position, the forces developed through the adillsiablo Coupling against said spring, said implement act through a maximum length of oollpllng means Comprising a lever pivotally atlever arm extending from pivot 13 to pivot tached at its lower end to said tractor, pivotal This permits a greater leverage ln arm l2 which 60 connecting means above said lower pivotal end acts to compress spring 52 attached to lever I2 on the level for Said Control rod, a member adat pivot 48 just above pivot 40. lustably positioned along said lever for attach- If a heavy implement is being used it may ment of said linkl and screw means'attached to thus the operator turns crank 58 to move slide 65 stlonlng Said n lembei' along Said level, whereby member 34 downward, thereby decreasing the movement of said member toward said lower plvlength of the leverage arm |2, that ls the disotal mounting of the lever decreases the levertance between pivots 13 and 4u, age arm through which said link acts on said The action of lever I2 with its adjustable spring in moving said control rod and movelength of arm is equivalent to changing spring 70 ment of said member away from said lower piveasy to compress. spring in moving said control rod.

The action of the adjustable length lever I2 3. A device of the character described for is superimposed on the regular hydraulic convarying the position of application of the forces link for actuating a compresa control rod of a hydraulic implement lift system for a tractor, comprising a lever pivotally mounted at its lower end to said tractor, means for connecting one end of said control rod and compression spring to said lever at a point above said tractor pivotal connection, a slide member movable along said lever for connecting said compression link with said lever, and screw means attached to said lever and said member for moving said member along said lever, whereby the effective length of said lever may be varied by moving said slide member along said lever.

4. Hitch means for connecting an implement to a tractor vehicle comprising upper and lower link means subject to compressive and tensile stresses in resisting turning movement of the implement due to the draft thereon, the upper of said link means being connected to said tractor through a variable length lever extending substantially vertically transverse to said upper link means; said variable length lever comprising a first member pivoted at its lower end to said tractor and having means positioned above said lower pivoted end for attaching a control rod and compression spring for a lift means for said hitch; said first member of the variable length lever being of a U-shape open at its lower pivotal connecting end and closed at its upper end; a second member movably-positioned along said first member from and toward said lower pivoted end of the first member; said second member comprising a block slidable within said U- shaped first member having flanges for guiding it in said U- haped member and means for pivotally connecting said upper link of the implement hitch means; and means for moving said second member along said first member, whereby the effect of the force applied by said upper link through said variable length lever to said control rod and compression spring for the lift means for said hitch may be varied.

5. Hitch means for connecting an implement to a tractor vehicle comprising upper and lower link means subject to compressive and tensile stresses in resisting turning movement of the implement due to the draft thereon, the upper of said link means being connected to said tractor through a variable length lever extending substantially vertically transverse to said upper link in a compression sion spring and means, said variable length lever comprising a said tractor and having means lower pivoted end for attaching a control rod and compression spring for a lift means for said hitch, a second member movably positioned along said first member from and toward said lower pivoted end of the rst member, and means for moving said second member along said rst member, said second member being pivotally connected to the forward end of said upper link means, whereby the effect of the force applied by said upper link to the control rod and compression spring for the lift means for said hitch may be varied; said first member of the variable length lever being of a U-shape open at its lower end and provided at its upper closed end with a rotary mounting for said means for moving said second member along said first member; said second member comprising a block slidable within said U -shaped first member having flanges for guiding it in said U-shaped member, a threaded aperture extending through said block for mounting said means for moving said second member along said first member, and a pair of spaced extending lugs for receiving and pivotally connecting with the forward end of said upper link; said means for moving said second member along said first member comprising a shaft mounted for rotation in said rotary mounting in the upper end of said first member, a threaded portion on said shaft threadedly received in said threaded aperture in the second member and a crank fixed to said shaft whereby rotation of said crank rotates said shaft to move said second member threadedly engaged therewith.

HENRY METZGER.

References Cited in the le of this patent UNITED STATES PATENTS Number Name Date 2,456,693 Fraga Dec. 21, 1948 2,460,847 Schwarz Feb. 8, 1949 2,462,588 Wondra Feb: 22, 1949 2,465,641 Gardner Mar. 29, 1949 2,515,637 Dooley et al. July 18, 1950 FOREIGN PATENTS Eliumber Country Date 520,484 Great Britain Apr. 25, 1940 

